1. Field of the Invention
The present invention relates to a computer system with data recovering, a method of managing data with data recovering and a managing computer for data recovering.
2. Description of the Related Art
Generally, in an information system, a backup operation is periodically made to recover data lost upon a trouble in a storage system, data corruption, an erroneous operation by a user.
For this, a backup and recovery technology using journaling (acquisition of updating history) is proposed. For example, U.S. patent application publication No. 20050015416, which is incorporated herein by reference, discloses backup and recovery technology using the journaling as follows:
A snapshot (full-backup or logical image such as differential backup) at a specific timing of a logical group (hereinafter referred to as journal group) including more than one data volume (data storing area) is acquired. Data written after that in the data volume is stored in a journal volume related to the journal group as journal (referred to as AFTER journal). Data at specific timing is recovered by applying of a series of the AFTER journals to the acquired snapshot in order of writing the AFTER journals. Generally, this is an example of a technology referred to as CDP (Continuous Data Protection).
Further, U.S. patent application publication No. 20050015416 discloses a method of canceling application of the AFTER journal to the snapshot when the recovered data is corrupted after application of the AFTER journal. U.S. patent application publication No. 20050015416 also discloses as follows:
Data at an area on which new data is overwritten upon applying the AFTER journal to the snapshot is saved in the journal volume. When application of the AFTER journal is cancelled, the data is recovered to the snapshot before the AFTER journal is applied in short time by applying the saved data (writing the saved data) to the original area to the snapshot to which the AFTER journal is applied. The saved data is referred to as BEFORE journal.
Japanese Laid-open Patent Application Publication No. 2004-252686 discloses a technology in which the AFTER journal and the BEFORE journal are acquired at the same time when the data from a host computer is written. This recovers past data by applying the BEFORE journal to the volume in use. The AFTER journal, the BEFORE journal, and meta data for managing the journals are simply referred to as journal. Further, the snapshot, which is a target to which the journal is applied when recovering, is referred to as base snapshot.
Further, a technology is disclosed in which lives of disk drives forming a storage system are expanded and a power consumption of a disk array of the system is reduced (for example, Japanese Laid-open Patent Application Publication No. 2005-157710). Japanese Laid-open Patent Application Publication No. 2005-157710 discloses a technology in which a managing computer controls a power for disk drives as follows:
The managing computer includes a disk control program for sending an instruction to the disk array to turn ON/OFF a power for the disk drives forming a specific logical volume. The storage system includes a power control instruction receiving program for receiving the ON/OFF instruction for the power source and a disk power control circuit for turning ON/OFF disk drives corresponding to the logical volume.